Thin, flat multicell batteries for use in radios, cameras and the like are well-known to the art. Such batteries are described, for example, in U.S. Pat. Nos. 3,734,780; 3,740,270; 3,770,504; 3,770,505; 3,784,410; and others. While various electrochemical systems are employed, the most common type is the Leclanche battery. The zinc employed as the anode is often in the form of zinc particles or dust held together by a suitable binder system. Zinc particles permit the use of less zinc than ordinarily would be used without the risk of embrittlement as a result of mercury amalgamation.
As a result of the manufacturing process employed in obtaining zinc particles and the large surface area exposed to air, zinc particles often contain a relatively high proportion of zinc oxide. While levels of zinc oxide of about 5% or more may not be deleterious for most uses, such an amount could be highly detrimental to battery operation and life.
The presence of an appreciable amount of zinc oxide can result in a pH in the electrolyte in the range of about 6. In this rage, insoluble zinc salts can form, decreasing the life of the battery or even causing total failure. If, however, the pH of the electrolyte remains close to the initial pH of about 4.8, the shelf-life is extended and attendant anode corrosion can be minimized.